updated 10:30 am EST, Tue March 8, 2011

Google Voice can make pure Internet calls

Google Voice users learned late Monday that the service now has a way of making purely Internet-based phone calls. Making a SIP call with a "sip:" prefix, the Google Voice phone number and @sip.voice.google.com skips the conventional phone network entirely, saving users cellphone minutes. Disruptive Telephony tested it and found that a call worked "great."

The development is relatively new and, according to Google's partner YATE (Yet Another Telephony Engine), was added on January 31 without any public mention.

Google hasn't publicized the addition, and it's not clear whether it wants to do so. Until Verizon backed away from earlier policies with 4G, it and many other carriers have actively blocked Skype. 3G lag and the limited capacity of the older networks have been officially blamed, although the FCC and critics have warned that it's likely for anti-competitive reasons to prevent cheaper calls and save users the need for a more expensive voice plan.

More officially supported pure VoIP Google Voice could lead to customers having the option of taking a call solely online but having a traditional phone number that anyone could reach without an Internet connection. Theoretically, it could also allow for higher-quality audio similar to Verizon's 4G calling. Android 2.3 already has support to make SIP calls directly from the contacts list instead of having to use an outside app such as Google Voice.